One interesting plotline could be a deeper exploration of the Hallows' true powers. Maybe the characters discover new ways to use the Elder Wand, Resurrection Stone, and Invisibility Cloak that J.K. Rowling didn't fully explore in the original series. Another could be a different take on the final battle against Voldemort, with the Hallows playing a more complex role.
Well, some fanfictions might have a plotline where the Hallows are actually linked to an ancient magic that was long forgotten. For instance, the Resurrection Stone could have the power to not just bring back the dead in a limited way as in the original, but to fully restore them if certain conditions are met. And the Elder Wand's origin could be traced back to a more mysterious source, leading to a whole new adventure for Harry and his friends.
One interesting plotline could be how Harry's character develops in a different way after absorbing the Hallows. Maybe he becomes more powerful than in the original series and uses this power to reshape the wizarding world. For example, he could use the combined power of the Hallows to end the discrimination between pure - bloods and half - bloods once and for all.
In certain fanfictions, Harry could use the Deathly Hallows to bridge the gap between the wizarding and muggle worlds. The Elder Wand could be used to create magical protections around muggle cities, protecting them from dark magic without muggles ever knowing. The Resurrection Stone might be used to bring back important muggle - born wizards who were killed by Voldemort, and they could then help in the fight. The Invisibility Cloak could be used to protect muggles who are in danger, like if Death Eaters were targeting them. This would create a whole new dynamic in the 'Harry Potter' universe where the two worlds are more intertwined.
One interesting plotline could be about the rebuilding of Hogwarts. After all the destruction in the war, seeing how the students, teachers, and even the magical creatures come together to restore the school to its former glory. It could involve new magical discoveries during the reconstruction process.
One interesting plotline could be exploring the untold stories of minor characters during the events of 'Harry Potter and the Deathly Hallows'. For example, how the students who stayed at Hogwarts coped with the final battle approaching. Another could be a different take on the search for the Horcruxes, perhaps with a new group of characters assisting Harry in unexpected ways.
One possible plotline could be that Harry discovers a way to communicate with Death as an entity. Maybe he stumbles upon an ancient magic that allows him to have conversations with Death. Through these interactions, he gains a deeper understanding of life and death, and this new knowledge helps him in his battles against Voldemort. For example, Death could give him insights into the Horcruxes and how to destroy them more effectively.
In the fanfiction, it could be that Harry's friendship with Death is a secret known only to a few. He has to hide it from most of the wizarding world because they would not understand. This secrecy could add a lot of tension to the story. For instance, when strange things start to happen around Harry, like people seeing shadowy figures or experiencing unexplained chills, some might suspect dark magic. But in reality, it's just a side - effect of his connection with Death. Harry would have to struggle to keep his friendship a secret while also using the knowledge he gains from Death to protect his friends and the wizarding world.
A possible plotline could be the apprentice's journey to understand the true nature of death. In the fanfiction, they could be on a quest to find out the secrets behind the veil in the Department of Mysteries. Along the way, they encounter various challenges and make new allies, all while trying to master their role as the apprentice of death.
One interesting plotline could be Harry fully exploring and mastering the powers that come with being the Master of Death. He might use these powers to reshape the wizarding world in ways that were not possible before, like eradicating dark magic at its source.
One great fanfiction could be where Harry Potter uses his status as the master of death and the Hallows to bring about a new era of peace in the wizarding world. He might use the Resurrection Stone to communicate with the dead founders of Hogwarts for advice on how to better educate young wizards and witches.
One common plotline is exploring what could have happened if different characters had made different choices during the events of Deathly Hallows. For example, what if Ron hadn't left Harry and Hermione in the forest? Another interesting one is delving deeper into the backstories of minor characters. Some fanfics might focus on how a particular minor Death Eater got involved in Voldemort's regime.